Immunohistochemical localization of transforming growth factor beta(1) and beta(2) in mouse testes during postnatal development

We examined age-related changes in the expression of transforming growth factor-beta(1) (TGF-beta(1)) and transforming growth factor-beta(2) in mouse testes. The mice were assigned to three age groups: 35, 50, and 75 days old. Paraffin embedded testis sections were processed for the standard streptavidin biotin peroxidase complex immunohistochemistry method. TGF-beta(1) expression increased in aging round spermatids over the time studied. There was no expression in 35-day-old Leydig cells, whereas strong expression of TGF-beta(1) was observed in 50-day-old Leydig cells. Expression decreased in 75-day-old Leydig cells. TGF-beta(2) expression was weak in 35- and 50-day-old mouse spermatids, but expression was greater in 75-day-old elongated spermatids. In Leydig cells, TGF-beta(2) expression was strong in both 35- and 50-day-old mice, whereas the expression of TGF-beta(2) was less in 75-day-old Leydig cells. Our results suggest that TGF-beta(1) and TGF-beta(2) may play significant roles in testicular functions and germ cell development in mice.